clojure

问题 I'm building a Compojure web application, and I'd like it to use functions from another Clojure project I wrote. I'm not at all familiar with Maven, and from what I've heard, it has a very steep learning curve. Unfortunately, everything I've seen suggests using a private Maven repo as a dependency and doesn't suggest an alternative. I'd really like to avoid struggling with Maven if possible. Does anyone know of an alternative? I'm currently using the latest version of Leiningen. 回答1: If the

问题 Is there a idiomatic / built-in way to flip the argument order that is passed to a function in Clojure? As I do here with the definition of a helper function: (defn flip [f & xs] (apply f (reverse xs))) (vector 1 2) ; [1 2] (flip vector 1 2) ; [2 1] 回答1: A flip function does exist in other functional languages, but it's easy enough to do in Clojure as well, and you've already done it! There are other ways to do it as well. And here is a discussion about it from the Clojure mailing list. 回答2:

问题 What is the purpose of the clojure reduced function (added in clojure 1.5, https://clojure.github.io/clojure/clojure.core-api.html#clojure.core/reduced) I can't find any examples for it. The doc says: Wraps x in a way such that a reduce will terminate with the value x. There is also a reduced? which is acquainted to it Returns true if x is the result of a call to reduced When I try it out, e.g with (reduce + (reduced 100)) , I get an error instead of 100. Also why would I reduce something

问题 Since both the java implementation ( OpenJDK ) and Android's virtual machine DalvikVM are opensource it must be possible to implement Sun's JavaVM on top Google's DalvikVM. This would make it possible to run JVM based apps and languages ( Clojure, Jython ) out-of-the-box on the android. Is there an ongoing effort to produce such an implementation of the Sun JVM? 回答1: The OpenJDK makes use of native code so it would be a non-trivial port... there is at least one VM (JikesRVM) that is written

问题 I use Maven 3 to create a new Scala project. As far as I understand, the way to create a new project with Maven is by: mvn archetype:generate Maybe I'm missing out something, but I couldn't find even one option that offers the simplest Scala project (like the one received by lein new app ... for Clojure, for example). Any help here? 回答1: You should be able to use mvn archetype:generate . You can choose, e.g., org.scala-tools.archetypes:scala-archetype-simple . You need to put in the number

问题 after posting a somewhat ambiguous question, I believe I have nailed that what I am wondering (I am a complete novice in FSMs). I would like to simulate a state space using finite state machines (possibly non-deterministic automata i.e. multiple next-state transitions allowed) in clojure. This is essentially my problem: Suppose we have these states Q={flying,cycling,running,driving} and we have the state durations for each during an average day D={120,30,30,60} - where for the sake of

问题 I'm building a Clojure program that includes an option dialog where the user can select the font used in an editor. Just like many other programs, I would like to present the user with a ComboBox where the dropdown list displays the font names in the font itself (e.g. 'Calibri' is displayed in the Calibri font, 'Arial' is displayed in Arial, and so on.) In the past in Java, I have used a cell factory to customize the appearance of each cell in the list. My translation into Clojure is not

问题 Installed Eclipse-Kepler on a Windows 8 box. Clojure and Leiningen already installed. Installed Counterclockwise. Started up, created test Clojure project, ran without debugger, and ran successfully under debugger. Messed with it a bit more, was in and out of the debugger several times. After one debugging session got "an error" (yes, I know I should have written it down, but failed to do so. Take pity upon the soul of this poor sinner...). After that every debugging session I tried to start

问题 I am am trying to setup LevelDB in a ring/compojure app, and looking for an idiomatic way to to access the opened db descriptor into each request. For example: (defn -main "I don't do a whole lot ... yet." [& args] (println "Opening LevelDB file in db/main") (with-open [main-db (db/open "db/main")] (println "Running server on port 3000") (run-jetty #'web/app {:port 3000}))) How do you access the main-db descriptor into the request handlers? ie.: (defroutes handler (GET "/test" [] (db/put main

问题 If the Ring request map key :scheme has value of :https , is it guaranteed that a HTTPS connection has been established and there were no certificate errors? 回答1: This is probably a question that relates to whatever servlet container you're using rather than ring. ring-servlet populates the :scheme key by getting a value from the HttpServletRequest: :scheme (keyword (.getScheme request)) The servlet specification has only this to say about getScheme : Returns the name of the scheme used to